Shallow depth storage tank



J. TRAPNELL 1,953,202

SHALLOW DEPTH STORAGE TANK April 3; 1934.

Filed Oct. is, 1935 2 Sheets-Sheet l gwumtw flbHN M. TRAPNELL' April 1934. JIM, TRAPNE-LL I r 1,953,202

Filed Oct. 16, 19:53 2 Sheets-Sheet 2 JOHN M TRAP/VEL;

"u I I l I l I I I I I I I I I I I I I I I I I I I I I I @Mmv%@ ditto: u n a- Patented Apr. 3, 1934 I 7 1,953,203 I snALLow DEPTH STORAGE TANK Johrillrif'lrapnell, Newnan, Ga., assignor to R. D. Cole Manufacturing 00., Newnan, Ga., a corporation of Georgia.

Application October 16, 1933, Serial No. 693,868

8 Claims.

This invention relates to elevated shallow depth storage tanks of that type which have the bottom supported by an approximately fiat sys-' tem of radial girders.

It is known that if the sheet metal sections which constitute the bottom of the tank are altogether flat, the stress of the load of water in the middle regions of these sections is so great that the supporting girders must be placed rela- 10 tivelyclose together. It is known also that if the sheet metal sections are so shaped as to transform a portion of the load into a tensional stress, the sheet metal sections are much better ableto support the load and the radial girders may be placed at a greaterdistance apart. In harmony with this principle, tanks have been designed in which the sheet metal sections between the radial girders have been made to bulge convexly downwardly, but in all instances in which such construction has been contemplated, the valleys formed by the convexed sections have run radially with respect to the tank.

Since it is essential that the sheet metal sections be supported transversely at a certain point or points between the periphery of the bottom and its middle, such supports have necessarily although disadvantageously divided the radial valleys each into a radial succession of pockets or depressions which it has been impossible to drain. Tanks which have been constructed following this principle have'accumulated quantities of silt in these pockets which could be removed only laboriously by means of a shovel.

The object of the present invention is to provide a bottom construction for elevated tanks adopting the principle of dished sections, for the purpose 1 increasing the load carrying capacity of the bottom, but constructing and arranging these sections so that they'will drain by gravity into a riser or other suitable conduit arranged-at the middle of the tank.

Other objects of the invention will appear as the following description of a practical embodi-- ment thereof proceeds.

Referring now to the drawings which illustrate and form a part of the following specfication' and throughout the several figures of which the same characters of reference have been used to designate indentical parts:

Figure l is a side elevation partly in section showing a tank constructed according to the principles of the invention;

Figure 2 is a bottom plan view looking up;

Figure 3 is a section taken along the line 3-3 of Figure zshowing the relation of the convex plates or trough sections to the underlying supporting structure I Figure 4 is a section taken along the line M of Figure 2, showing the details of construction of the radial drainage trough;

Figure 5 is a cross section taken along the line 5-5 of Figure 4;

Figure 6 is a perspective view of the trough;

-Figure '7 is a perspective view of one of the sections oithe several annulee which constitute the bottom arrangement; and

Figure 8 is a perspective view showing a detail of theends of the gillage beams which are cut away for the reception of the trough.

Referring now in detail to the several figures the numeral 1 represents a tank, the shell 2 of which may be of any desired shape, but is here shown as being oval on top and merging into a side wall 3 which may be cylindrical or substantially so. v

The tank is supported upon a radial system of horizontal girders 4 emanating from a central tower 5 which encloses a riser 6 through which the tank may be filled or drained. The girders 4 are suitably supported on ground columns 7. Figure 2 shows that the angles between adjacent girders are intersected preferably symmetrically by means of gillage beams 8 which rest upon the top flanges of said gillage beams. The height of the web portions 9 decrease progressively from the outer region of the tank toward the center so that the bottoms of the troughs 10 which rest upon the web portions slope down toward the middle of the tank. The sides 20 of the troughs, as will appear from Figure 6, are higher near the middle of the tank than adjacent the outer ends of said trough, so that when the troughs rest with their bottoms inclined on the web portions, the tops, whichi'est across the flanges of the gillage beams are substantially level.

The central tower 6 is closed by a circular plate 12 at the same. level as or at a lower level than the innenends of the troughs 10, and through said i plate extends the riser 6. The plate 12 therefore forms the bottom of a central sump into whichall of the troughs 10 are adapted to drain, the

sump draining by way of the riser. The spaces between the radial girders and gillage beams are.

closed by steel plates 13 one of which is shown in Figure 7, which plates are shaped as annular sectors and dished or concaved on the inside in a circumferential direction with respect to the bottom of the tank. Each of said plates is formed with longitudinal flanges 14 and 15 adapted to lie upon the gillage beams and to be riveted or otherwise suitably secured in water-tight manner. The ends of the plate 13 are provided with arcuate flanges 16 and 1'7 adapted to be riveted or otherwise secured to the sides 18 of the trough. The sides of saidftrough are cut to form arcuate apertures 19 having their lower edges preferably con-- forming to and flush with the inner surfaces of the plates '13, so that the latter can freely drain through the apertures 19 and into the body of the trough. It is thus apparent that I have produced a substantiallyflat bottomed tank, the bottom of which is carried by radial girders supported upon ground columns, the bottom being formed as concaved annuli each comprising a series of dished plates supported at their ends by the radial girdersand longitudinally by the gillage-beams in combination with a trough having openings .with which the annular. sectors register and into which they can freely drain.

It is of course to be understood that the nature of the means by which communication is provided between the dished plates and the troughs 10 is a matter of choice. and expediency and does not concern itself particularly with the breadth of the inventive concept. 1

The ends of the radial girders 4 extend beyond the periphery of the shell of the tank and ailord a convenient -supportng structure for the floor 21 of a balcony 22.

While I have in the above disclosure described what I believe to be a preferred and practical embodiment of my invention, it is to be understood that numerous alternative constructions may be employed embodying the principles of the present invention'without transcending the scope of the appended claims.

What I claim'is:

1. Tank construction comprising a shell having a bottom comprising means-providing a plurality of concentric substantially annular valleys, radial girders supporting said bottom, and radial troughs intersecting 'said annular valleys and into which the latter are arranged to dra 2. Tank construction comprising a shell having a bottom comprising means providing a plurality of concentric substantially annular valleys, radial girders supporting said valleys and radial troughs above said girders intersecting said annular valleys and into which the latter are arranged to drain.

3. Tank construction comprising a shell having a bottom comprising a plurality of radial girders, a plurality of beams intersecting the angles between said girders and supported upon said girders, series of dished plates in concentric annular arrangement supported by said beams, radial troughs above said girders and supported by the end portions of said beams, to the sides of which the ends of adjacent plates are secured in watertight manner, the sides of said troughs being provided with openings flush with the lowermost dip of the upper surfaces of said plates providing for the drainage of said plates into said troughs, the latter being directed toward a, central point of discharge.

4. Tank construction as claimed in claim 3, said beams having their adjacent ends cut away in part, above said girders affording a seat for said trough.

5. Tank construction as claimed in claim 3, said beams having their adjacent ends cut away in part above said girders, leaving web portions of progressively diminishing height from the middle ofthe tank toward the periphery thereby providing a sloping seat for said girders inclined downwardly toward the middle of said tank.

6. Tank construction as claimed in claim 3, said beams having their adjacent ends cut away in part above said girders, leaving web portions of progressively diminishing height from the middle of the tank toward the periphery, thereby providing a sloping seat for said girders inclined downwardly toward the middle of said tank, the

said girders.

JOHN M. TRAPNELL. 

